In recent times, the use of light weight battery materials and cost efficient battery constructions have been of prime interest to the automotive and battery industries. In particular, cost-effective battery designs are of paramount importance for electric vehicular systems. For electric vehicles and other bulk energy storage applications, cost justification of a battery system is highly sensitive to the initial battery cost and to the life-cycle cost. The present invention seeks to provide a new electrochemical cell construction which reduces the initial costs and extends operating life for a battery system through the utilization of new manufacturing techniques, new weight-reducing materials and new integration of components.
A new cell design and construction has resulted from the achievement of the above objectives, which design and construction features amongst other novelties:
1. An integral separator and spacer to reduce space, parts and cost.
2. A reduction in gas entrapment with the use of the new separator-spacer design.
3. An integral conductive/non-conductive (dielectric) coextruded plastic electrode which is both light weight and inexpensive to manufacture.
4. Reduction and/or elimination of parasitic shunt currents.
5. Male/female stacking and integration of parts and conduits to provide ease and compactness of assembly.
6. A two-piece interleaved bipolar battery assembly which is more compact, light weight, leakproof, easy to assemble and low cost.
7. A safer battery design and construction which reduces the possibility of spilling corrosive materials should compartments housing these materials rupture.
The subject inventive method is useful in the manufacture, construction and assembly of many different kinds of composite sheet materials and in particular, electrochemical cells. The invention should be interpreted as not being limited to a specific system, construction, or use.
The method of this invention is of particular interest for constructing electrode sheets for a circulating zinc-bromine battery, constructed in accordance with the teachings advanced in the aforementioned U.S. Patent to: Agustin F. Venero, entitled: Metal Halogen Batteries and Method of Operating Same, U.S. Pat. No. 4,105,829, issued: Aug. 8, 1978, and assigned to the present assignee.
The above-mentioned battery system is of particular interest because of its low cost and availability of reactants, its high cell voltage and its high degree of reversiblity.